SAS Removal Alternative

Bought my 05 a couple of months ago and have been reviewing the extremely helpful information on this site.
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I Installed FMF mufflers and am in the process of re-jetting and thought why not do the SAS removal since the bike was apart? After looking at the threads on this subject and looking at how the system is designed, it seems like plugging the large hose that goes from the reed valves to the valve on the back of the air box would accomplish the same thing without all of the hassle. Others have suggested plugging the individual inlets to the reed valves but it seems to me that I could accomplish the same thing with one plug and all of the components would be there if I had to reconnect it. I just want to stop the airflow into the exhaust ports. I know I would still have all of the clutter but this is not a problem for me. Is there any reason this would not work?

I believe most here would agree with you, plugging the hose basically accomplishes the same task. Only downside,as you stated, is that you still have the clutter. My evap can is a gonner but the SAS is still intact until I have the first service done, after that I plan on removing the SAS one way or another and then work on the jetting.

Anyone have a pic of said vacuum hose? Behind the airbox? Can I get to it from under the seat?

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When the right side of the airbox and engine are revealed (remove right fairing & tank) you will note two brass barbs on the intake manifolds (there are 2 on each manifold, 1 on each side). One of these is the vacuum port that controls the rear valve for the SAS. The other goes to a blind plug on the same valve.. Retain both lines, just plug the line to the valve with a suitable machine screw & clamp. These lines are the ones used to balance the carbs so don't remove them, just make sure they are plugged & secure.

All you need to do to make it inoperative is remove & plug the small vacuum hose on the valve behind the airbox. Leaves the clutter but stops it working.

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Plugging the vacuum hose doesn't stop it from working, it will make it work all the time. The vacuum signal to the valve shuts off the flow of air to the exhaust under high vacuum condtions (decelleration) to prevent backfires.

If you just plug the vacuum hose, the system will work all the time and you will have backfiring on decell.

Saw no reason to keep all that stuff, so I scrapped it all on first service no SAS no Cannister. My only issue with my bike was the sketchy carburation, and now its sweet like it should have been out of the box...

I dunno. It sure warmed my heart to see that big pile a crap lying dead on the shop floor at my first service. Bike runs so nice without it. Take it off. Take it all off.

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+1. It's easy, too, with one exception: getting the blanking plate onto the front cylinder without removing the oil tank is an effing PITA. It helps a little if you remove oil tank bolts, but you still should make sure the kids are in bed so they don't learn the f-word from you, or get hit in the head by a flying wrench.

I started this thread and in a subsequent response to another thread said that just plugging the one line did not work. You need to disconnect the valve from the air box and plug both sides in order to render the system inoperative. The reasons to do this as opposed to taking everything off are:
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1. Ease of completing the task.
2. Being able to re-assemble the system if you have to satisfy future govt. mandates.
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I live in the peoples <st1lace w:st="on"><st1laceType w:st="on">republic</st1laceType> of <st1laceName w:st="on">California</st1laceName></st1lace> and cannot predict what the California Air Resources Board may mandate re. emissions requirements for the resale of motorcycles.
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Plus it is a lot of work to take everything off, plug etc when you can do it in about 5 minutes if you go the alternative route mentioned.

I simply epoxied a penny over the inlet of the SAS system of my '05 640A - jetting with taht !@#$ system in place is impossible. Simply too much cold air being injected into the exhaust manifold. I thought of removing the clutter, but decided that the route I chose was better. While I have an xtra x ounces of weight on board, I also only have 1 vacum post modifictaion to worry about vs. almost 1/2 dozen if I'f removed the system.

I just put FMF's on my 950 also, and as a this is my daily driver I do not have time right now to tackle the SAS removal job. I'll wait until there is a very cold snow spell. Any pics of this quick, temp fix would be greatly appreciated.

1. The system operates by a valve that is controlled by engine vacum. It is designed feed O2 into the exhaust to keep the cat converter happy and to make sure all the tree hugging wankers smile those naive left wing grins of idealism when staring at their emissions testing gear.

The system CAUSES backfires and decel pops (that you hear with a thinner walled more straight thur aftermarket slipon vs the hunks of baffled sewer pipe most bikes come with for exhuast systems these days) thru injecting a sudden volume of air into a hot manifold 'full' of unburned dead dinos.

When open the valve allows fresh air to be sucked in thru a filtered air inlet thru the valve into the exhaust manifold (plural on the 950?). You could use the SAS/SLS system diagram in the repair manual to find the air inlet, but if it's anything like the 640A the air inlet is a rubber hose that terminates thru a large rubber grommet in the downtube on the rhs of the bike frame. Simply yank the hose/grommet out. On the end you should find a small black plastic cylinder with a metal screened inlet. That is the air inlet for the entire system.

I simply took a penny, lathered it with 5 min epoxy and secured it over the inlet port. the next day, reinserted the hose/inlet into the downtube, pushed in the grommet and end of story. KTM-Sommer sells a virtually free plastic or alu plug you can use to snap in place of the inlet filter, but the shipping cost to NA would cost far more than the unit is worth.

With this plugged and an aftermarket slipon, you will notice an improvement in idle smoothness and no more backfiring and popping on decel. You can now tweak your jetting without cursing the sillyservants at the EPA and EU. To test the improvement you see, tweak the throttle of a running bike with the air inlet as is and then with your thumb over it. It does no harm to the system, no vacum leaks to worry about, etc, etc. It is also easy to switch back when the testers come calling or upon resale to the enviromentally conscious.

KTM Sommer has a 'Tip" in their catalog that shows the plugging process. It may differ somewhat for a 950, but the basic operation should be the same.

Didn't scrap my SAS just disabled it. With the seat off and looking down on the left side of the air box (clutch side) you should see a large diameter rubber hose coming off the back of the airbox. Remove hose, apply silicone to a RED colored wire nut and press into the hose. Take second RED wire nut apply small amount of silicone sealant and screw onto the nub sticking out of air box until snug. Let sit over night. This was such a simple thing to do and it worked miracles on my bike especially in the decel popping department. I hated that noise. There is absolutely no popping on decel at all. It is gone. You can lay off the throttle at 100 or 10 with the same results. Plus if by any chance my state makes emmission testing manditory I'll just hook the airbox back together and voila!!! Thaen take it apart when I get home.

IS there any issue about removing the SAS without an aftermaket exhaust. Other reason than " the cat need it ". Don't forget that catalytic converter's appeared way before SAS system. It can probalbly reduce the life of the cat.

For those who hasn't done their homeworks Secondary Air System. Read your manual !